The present invention relates to a prosthetic interpositional device/coupler. In the prior art, it is generally known to interpose some structure between the head and neck of a prosthesis for various reasons. However, Applicant is unaware of any such device having structure like that of the present invention, nor for the specific purposes thereof.
The following prior art is known to applicant:
U.S. Pat. No. 4,005,495 to Locke et al. discloses a ceramic cap bone prosthesis and method of implantation. The invention consists of a cap 1 designed to be mountable over a neck 2 which comprises the femoral head of the existing bone which has been surgically shaped to receive the cap 1. A thrust plate 4 is mounted on the bone 10 through an opening formed therein, with the thrust plate 4 being used to assist in locking the cap 1 on the neck 2. The present invention differs from Locke et al., among other reasons, as including embodiments of an interpositional device/coupler which annularly engages the cap as well as the neck of a prosthesis rather than of living bone tissue.
U.S. Pat. No. 4,173,797 to Langlais et al. discloses a prosthesis for arthroplasty of the hip which includes a thin metal cup 16 having a lateral skirt member 18 which cup 16 is designed to be mountable over the head 22 of the existing femur 1 with this head 22 having been machined to conform to the configuration of the cup 16. Again, this is different from the teachings of the present invention, since the inventive interpositional device/coupler is designed to be interposed between a cap and neck of a prosthesis.
U.S. Pat. No. 4,227,265 to Frey discloses a bone implant with plastic insert between elements of different mechanical properties. The plastic insert consists of a cap-like sleeve 4 designed to be mountable over the neck of a stem 1 and to engage, with its outer surfaces, the inner surfaces of a cavity formed in the head 2. A screw 3 is used to secure the head 2 to the stem 1. The present invention is different from the teachings of Frey, among other reasons, as requiring the interpositional device/coupler to be made of metal, as allowing the inner and outer surfaces of the interpositional device/coupler to subtend differing angles and as allowing the inner and outer surfaces thereof to have differing surface textures.
U.S. Pat. No. 4,676,797 to Anapliotis et al. discloses a unit for a resection prosthesis consisting of a prosthesis made up of a plurality of sections including, for example, an intermediate member 5 designed to couple together a head member 1 and a further intermediate member 9. The present invention is clearly distinct from the teachings of this patent, among other reasons, as including an interpositional device/coupler designed to be directly interposed between the head and neck of the prosthesis.
U.S. Pat. No. 4,687,488 to Frey discloses a femur head prosthesis including a joint head 5 having a sleeve welded thereto by means of a weld 12. This is different from the teachings of the present invention wherein the head includes pre-existing inner surfaces which are engaged by an insertable interpositional device/coupler into which may be inserted the neck of the prosthesis. Other distinctions exist.
European Patent Application No. 144,209 to Weightman, et al. discloses an endoprosthetic bone joint component device which includes a plastic part 30 designed to be interposed between the neck 12 of a prosthesis and the head 20 thereof, with the head 20 preferably being made of ceramic and with the neck 12 preferably being made of metal. The present invention differs from the teachings of this European Patent Application, among other reasons, as providing a metallic interpositional device/coupler having inner and outer surfaces which may subtend differing angles, with these inner and outer surfaces also preferably having differing surface textures.
European Patent Application No. 193,681 to Elloy discloses joint prostheses including a plastic sleeve 7 or 13 designed to be interposed between a head and neck of a prosthesis. The present invention differs from the teachings of Elloy for the same reasons set forth hereinabove concerning U.S. Pat. No. 4,227,265 to Frey and European Patent Application No. 144,209 to Weightman, et al.
European Patent Application No. 202,141 to Flegeau, et al. discloses a femoral head for a hip joint prosthesis including a head with a sleeve device mounted thereto. The sleeve device has a supporting ledge 13 for the head 11. The present invention differs from the teachings of Flegeau, et al. for reasons including the differing textures of the inner and outer surfaces thereof.
German Auslegeschrift 25 24 923 to Frey discloses a hip joint prosthesis including a metallic sleeve 3 interposed between the stem 5 and the head 1 thereof. The present invention differs from the teachings of Frey for reasons including the differing surface textures of the inner and outer surfaces of the sleeve of the present invention.
German Offenlegungsschrift 26 18 763 to Ribonet, et al. discloses a joint prosthesis including a head 1 mounted to a stem 6 via a sleeve 4 designed to be soldered to the stem 6 to prevent relative translational motion. The present invention differs from this teaching for reasons including the fact that the inventive interpositional device/coupler is frictionally engaged to the neck of the prosthesis without soldering, and, additionally, due to the differing surface textures of the inner and outer surfaces.